Positive toners containing long chain hydrazinium compounds

Abstract

Disclosed are positive toners comprised of a toner resin, pigment or colorant, and as a charge inducing material, long chain hydrazinium compounds of the following formula: ##STR1## wherein R 1 is a hydrocarbon radical containing from about 8 to about 22 carbon atoms, R 2 and R 3 are independently selected from hydrogen groups or hydrocarbon radicals containing from about 1 to about 22 carbon atoms and A is an anion which in a preferred embodiment is selected from halides such as chloride, bromide, iodide, sulfate, sulphonate, phosphate, and nitrate. These toners, together with carrier materials can be used to develop images in electrophotographic systems.

What is claimed is: 
     
       1. A method of imaging comprising forming an electrostatic latent image on a photoreceptor, contacting the image with positively charged developer comprising a positively charged resin material, a colorant or pigment, a negatively charged carrier, and a long chain hydrazinium charge inducing compound of the following formula, which compound is blended into the resin material or coated on the pigment in an amount of from about 0.1 weight percent to about 10 weight percent: ##STR3## wherein R 1  is a hydrocarbon radical containing from 8 to 22 carbon atoms, R 2  and R 3  are independently selected from hydrogen or hydrocarbon radical containing from 1 to 22 carbon atoms, and A is an anion selected from halides, sulfate, sulphonate, phosphate and nitrate, subsequently transferring the developed latent image to a substrate, and permanently affixing the image thereto. 
     
     
       2. A method of imaging in accordance with claim 1 wherein the long chain hydrazinium compound is N,N-dimethyl, N-cetyl hydrazinium chloride, N,N-dimethyl N-lauryl hydrazinium chloride N,N-dimethyl N-cetyl hydrazinium para-toluene sulfonate and N,N-dimethyl N-lauryl hydrazinium bromide. 
     
     
       3. A method of imaging in accordance with claim 1 wherein the resin is a copolymer of styrene/n-butyl methacrylate, and the carrier is steel coated with polyvinylidene fluoride, or vinyl fluoride resins. 
     
     
       4. A method in accordance with claim 1 wherein the colorant or pigment is coated with the long chain hydrazinium compound in an amount of from 1 percent to 6 percent by weight of pigment. 
     
     
       5. A method in accordance with claim 1 wherein the photoreceptor is charged negatively. 
     
     
       6. A method in accordance with claim 5 wherein the photoreceptor is polyvinyl carbazole. 
     
     
       7. A method in accordance with claim 1 wherein 10 to about 200 parts by weight of carrier to 1 part per weight of toner is present.